Proline Promass 80H, 83H
20
Hauser
Pressure loss
Pressure loss depends on the fluid properties and on the flow rate. The following formulae can be used to
approximately calculate the pressure loss:
Pressure loss coefficients for Promass H
a0004607
Pressure loss diagram for water
Reynolds number
a0003381
Re
≥
2300 *
a0004631
Re < 2300
a0004633
Δ
p = pressure loss [mbar]
ν
= kinematic viscosity [m2/s]
m = mass flow [kg/s]
ρ
= fluid density [kg/m3]
d = inside diameter of measuring tubes [m]
K to K3 = constants (depending on nominal diameter)
* To compute the pressure loss for gases, always use the formula for Re
≥
2300.
DN
d [m]
K
K1
K3
8
8.51
⋅
10
–3
8.04
⋅
10
6
3.28
⋅
10
7
1.15
⋅
10
6
15
12.00
⋅
10
–3
1.81
⋅
10
6
9.99
⋅
10
6
1.87
⋅
10
5
25
17.60
⋅
10
–3
3.67
⋅
10
5
2.76
⋅
10
6
4.99
⋅
10
4
40
25.50
⋅
10
–3
8.75
⋅
10
4
8.67
⋅
10
5
1.22
⋅
10
4
50
40.50
⋅
10
–3
1.35
⋅
10
4
1.72
⋅
10
5
1.20
⋅
10
3
Pressure loss data includes interface between measuring tube and piping
Re =
p
n r
· d ·
·
4 · m
D
n
r
p = K ·
· m ·
0.25
1.75
–0.75
· K3 · m
2
r
D
p = K1 ·
· m
n
·
K3 · m
2
r
1000
100
10
1
0.1
0.01
0.1
1
10
100
[mbar]
[t/h]
DN 40
DN 50
DN 25
DN 15
DN 8
